CN101795005B - Storage battery energy storage conditioning device - Google Patents

Abstract

The invention relates to a battery energy storage regulating device, which is characterized in that it comprises: at least two charging and discharging management systems, the AC sides of which are all connected in parallel to a common bus, and then connected to the high-voltage main bus through a transformer; The DC terminal of each charge and discharge management system is connected to a battery pack, and the battery pack is controlled to perform active power and reactive power at the PCC point formed with the high-voltage main busbar and the common busbar within the range of upper and lower limit voltage values. Two-way adjustment to stabilize the voltage and frequency of the PCC point; a system main monitor, which exchanges information with each of the charge and discharge management systems through several CAN interfaces, and controls the external The standby power supplies power to the high-voltage main bus or controls unloading charges to consume the electric energy output by the high-voltage main bus, so as to stabilize the voltage and frequency of the PCC point. The invention is easy to realize, saves cost, is suitable for forming an independent power supply system with a megawatt-level wind turbine, and is suitable for power supply of offshore oil field platforms and remote areas.

Description

A battery energy storage regulator

technical field

The invention relates to a power conditioning device, in particular to a battery energy storage regulating device (Power Conditioning System, PCS).

Background technique

my country's power grid is still unable to cover all regions of the country, such as remote areas, offshore oil field platforms, etc. This is because long-distance power transmission will not only cause a lot of power loss, greatly increase costs, but also be very difficult to achieve. As we all know, offshore and some remote areas are rich in wind resources. If wind resources can be effectively utilized and an independent power supply system can be established, the difficult problem of "island power grid" power supply can be well solved. However, due to the intermittent, fluctuating and uncontrollable characteristics of wind energy, a battery energy storage regulating device is needed to balance the fluctuation of the wind power of the fan, so as to stabilize the output voltage and frequency of the independent power supply system and improve the power quality. As far as the existing technologies are concerned, the battery energy storage regulating device suitable for forming an independent power supply system with kilowatt-level wind turbines has been applied, but the battery energy storage regulating device suitable for forming an independent power supply system with megawatt-level wind turbines has not yet , and the voltage and frequency fluctuations of independent wind power systems ranging from kilowatts to megawatts are increasing, and the voltage and frequency stability control of the system is facing greater challenges. More superior control methods and reasonable system structures are needed to ensure system stability. sex.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a battery energy storage regulating device that is easy to implement, saves cost, and is suitable for forming an independent power supply system with a megawatt wind turbine.

In order to achieve the above object, the present invention adopts the following technical solutions: a battery energy storage regulating device, which is characterized in that it includes: at least two charge and discharge management systems, the AC sides of which are all connected in parallel to a common bus, and then Connected to the high-voltage main bus through a transformer; the DC terminal of each charging and discharging management system is connected to a battery pack, and controls the PCC formed between the battery pack and the high-voltage main bus and the common bus within the upper and lower limit voltage ranges two-way adjustment of active power and reactive power, so that the voltage and frequency of the PCC point are stable; a system main monitor, which performs information interaction with each of the charging and discharging management systems through several CAN interfaces, and according to the described The instructions of the charging and discharging management system control the external backup power supply to supply power to the high-voltage main bus or control the unloading charge to consume the electric energy output by the high-voltage main bus, so as to stabilize the voltage and frequency of the PCC point.

Each of the charging and discharging management systems includes: a voltage source inverter, which performs bidirectional adjustment of active power and reactive power between it and the PCC point, so as to stabilize the voltage and frequency of the PCC point; several electric energy element sampling The device collects the actual electric energy elements of the high-voltage main bus, the electric energy elements on the common bus between the voltage source inverter and the transformer, and the voltage at both ends of the battery pack; the analog-to-digital conversion module converts the electric energy The various electric energy elements collected by the element sampler are converted into digital signals; a DSP core controller, which is preset with the PCC point voltage and frequency value, and the upper and lower limit voltage values at both ends of the battery pack; the DSP The core controller controls the voltage and frequency of the PCC point to a preset value according to the electric energy element input by the analog-to-digital conversion module, and simultaneously judges whether the voltage value at both ends of the battery pack exceeds the preset upper and lower limit voltages value to control the operation of the voltage source inverter and/or the system master monitor.

The electric energy elements collected by the electric energy element sampler include voltage, frequency and current.

When the DSP core controller judges that the actual voltage and frequency values of the PCC point are greater than the preset voltage and frequency values, and the voltage values at both ends of the battery pack are within the preset upper and lower limit voltages When within the range, the voltage source inverter absorbs active power to stabilize the voltage and frequency of the PCC point to a preset value.

When the DSP core controller judges that the actual voltage and frequency value of the PCC point are greater than the preset voltage and frequency value, and the voltage value at both ends of the battery pack is equal to the preset upper limit voltage value The DSP core controller controls the unloading load through the system main monitor to consume the electric energy output by the high-voltage main bus, so that the voltage and frequency of the PCC point are stabilized to preset values.

When the DSP core controller judges that the actual active power value is less than the preset rated active power value, and the voltage value at both ends of the battery pack is within the preset upper and lower limit voltage range, the voltage source reverses The active power generated by the transformer stabilizes the voltage and frequency of the PCC point to the preset value.

When the DSP core controller judges that the actual active power value is less than the preset rated active power value, and the voltage value at both ends of the battery pack is within the preset upper and lower limit voltage range, the voltage source reverses The converter sends active power, and at the same time, the DSP core controller starts the external backup power supply through the system main monitor to supply power to the high-voltage main bus, so that the voltage and frequency of the PCC point are stabilized to preset values.

When the DSP core controller judges that the actual active power value is less than the preset rated active power value, and the voltage value at both ends of the battery pack is equal to the preset lower limit voltage value, the DSP core control The controller starts an external backup power supply through the system main monitor to supply power to the high-voltage main bus, so that the voltage and frequency of the PCC point are stabilized at preset values.

It also includes a host computer, which interacts with the main monitor of the system through the RS485 interface, so as to remotely monitor and control the charging and discharging management system; Perform information interaction with the system main monitor to perform man-machine dialogue and remote control on the charge and discharge management system.

The present invention has the following advantages due to the adoption of the above technical scheme: 1. Since the present invention includes at least two charging and discharging management systems corresponding to the battery pack, and each charging and discharging management system adopts a DSP core controller, wherein the preset There is a rated active power value and reactive power value, as well as the upper and lower limit values of the voltage at both ends of the battery pack. The DSP core controller calculates the actual active power value and reactive power value of the high-voltage main bus according to the electric energy elements input by the analog-to-digital conversion module. Compare the actual active power value and reactive power value with the preset rated active power value and reactive power value, and at the same time judge whether the voltage value at both ends of the battery pack exceeds the preset voltage upper and lower limits , to control the two-way exchange of active power and reactive power between the battery pack and the PCC point through the voltage source inverter, so the frequency and voltage of the PCC point can be easily controlled to maintain stability, thereby improving the output quality of electric energy. Moreover, it is also suitable for forming an independent power supply system with megawatt wind turbines. 2. Since each battery pack of the present invention can be directly inserted into the DC terminal of the corresponding charging and discharging management system, and each charging and discharging management system is connected in parallel to a common bus, and connected to the high-voltage main bus through a transformer respectively, therefore The rated capacity of each charging and discharging management system can be reduced for easy implementation. The invention is easy to realize, saves cost, is suitable for forming an independent power supply system with a megawatt-level wind turbine, and is suitable for power supply of offshore oil field platforms and remote areas.

Description of drawings

Fig. 1 is a structural representation of the present invention

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in FIG. 1 , the present invention includes at least two charging and discharging management systems 1 , a system main monitor 2 and several CAN interfaces 3 . Wherein, the charging and discharging management system 1 corresponds to the battery pack 4 one by one, and the DC terminal of each charging and discharging management system 1 is connected to the corresponding battery pack 4, and controls the corresponding battery pack 4 to charge and discharge. Each charging and discharging system 1 performs information interaction with the system main monitor 2 through a CAN interface 3 respectively, and the AC side of each charging and discharging management system 1 is connected in parallel to a common bus 5, and then connected to the high-voltage main bus through a transformer 6 7 (equivalent to the grid), the contact between the common bus 5 and the high-voltage main bus 7 forms a PCC point (Point of common coupling, public coupling point), the stability of the voltage and frequency value of the PCC point ensures the power consumption of the load 11 Stablize. In this embodiment, the battery pack 4 can use any one or more of existing lithium titanate batteries, sodium-sulfur batteries, flow batteries, lithium batteries and lead-acid batteries.

Each charging and discharging management system 1 of the present invention includes a voltage source inverter 8 , several electric energy element samplers 9 , an analog-to-digital conversion module 10 and a DSP core controller 11 . Among them, the voltage source inverter 8 performs bidirectional adjustment of active power and reactive power with the PCC point according to the instructions of the DSP core controller 11. When the voltage source inverter 8 absorbs active power, the remaining The electricity is stored in the battery pack 4; when the voltage source inverter 8 generates active power, that is, the battery pack 4 supplies power to the high-voltage main bus 7 through the common bus 5. The electric energy element sampler 9 is used to collect the actual electric energy elements of the high-voltage main bus 7 , the electric energy elements on the common bus 5 between the voltage source inverter 8 and the transformer 6 , and the voltage Vdc at both ends of the battery pack 4 . The electric energy element generally includes voltage, frequency and current. In this embodiment, the electric energy element sampler 9 may be a voltage Hall sensor and a current Hall sensor. The analog-to-digital conversion module 10 converts various electric energy elements collected by the electric energy element sampler 9 into digital signals. The PCC point voltage and frequency values, as well as the upper and lower limit voltage values at both ends of the storage battery pack 4 are preset in the DSP core controller 11 . The DSP core controller 11 controls the PCC point voltage and frequency to a preset value according to the electric energy element input by the analog-to-digital conversion module 10, and simultaneously judges whether the voltage value at both ends of the battery pack 4 exceeds the preset upper and lower limit voltage values to control Operation of the voltage source inverter 8 and/or system master monitor 2 .

The control situation of the DSP core controller 11 to the system main monitor 2 is: once it is judged that the voltage value at both ends of the battery pack 4 is greater than the preset upper limit voltage value, the DSP core controller 11 controls the unloading load consumption through the system main monitor 2 The electric energy output by the high-voltage main busbar 7 is dropped, so that the voltage and frequency of the PCC point are stabilized at preset values. If it is judged that the voltage value at both ends of the battery pack 4 is less than the preset lower limit voltage value, the DSP core controller 11 controls the external backup power supply to start through the system main monitor 2, and supplies power to the high-voltage main bus 7, so that the voltage and frequency of the PCC point Stable is the default value.

In the above-mentioned embodiment, the present invention also includes a host computer 12, which performs information interaction with the system main monitor 2 through the RS485 interface 13, so as to remotely monitor and control the present invention. The upper computer 12 also includes a man-machine interface 14, which exchanges information with the system main monitor 2 through the CAN interface 3, so as to perform man-machine dialogue and remote control on the charging and discharging management system 1 .

The present invention regulates the work of electric energy as follows:

1) When the DSP core controller 11 judges that the actual voltage and frequency value of the PCC point are greater than the preset PCC point voltage and frequency value, and the voltage values at both ends of the battery pack 4 are within the preset upper and lower limit voltage ranges, The voltage source inverter 8 absorbs active power, that is, the voltage source inverter 8 stores the remaining electric energy in the high-voltage main bus 7 in the battery pack 4, so that the voltage and frequency of the PCC point are stabilized to preset values.

2) When the DSP core controller 11 judges that the actual voltage and frequency value of the PCC point are greater than the preset PCC point voltage and frequency value, and the voltage value at both ends of the battery pack 4 is equal to the preset upper limit voltage value, the DSP core control The controller 11 controls the unloading load through the system main monitor 2 to consume the electric energy output by the high-voltage main bus 7, so that the voltage and frequency of the PCC point are stabilized to preset values.

3) When the DSP core controller 11 judges that the actual voltage and frequency value of the PCC point is less than the preset PCC point voltage and frequency value, and the voltage value at both ends of the battery pack 4 is within the preset upper and lower limit voltage range, the voltage source The inverter 8 generates active power, that is, the voltage source inverter 8 supplies the electric energy stored in the battery pack 4 to the high-voltage main bus 7 through the common bus 5, so that the voltage and frequency of the PCC point are stabilized to preset values.

4) When the DSP core controller 11 judges that the actual voltage frequency value of the PCC point is less than the preset PCC point voltage and frequency value, and the voltage value at both ends of the battery pack 4 is equal to the preset lower limit voltage value, the DSP core controller 11 Start the external backup power supply through the system main monitor 2 to supply power to the high-voltage main bus 7, so that the voltage and frequency of the PCC point are stabilized to the preset values.

The invention realizes two-way regulation of active power and reactive power between PCC points, that is, four-quadrant operation. When the independent power supply system composed of the present invention and the megawatt-level wind turbine is disturbed, the present invention can dynamically balance the active power and reactive power of the independent power supply system within the rated range, and control the frequency and voltage stability of the PCC point as the preset value .

Above-mentioned each embodiment is only for illustrating the present invention, and wherein the structure of each part, connection mode all can be changed to some extent, and all equivalent transformations and improvements carried out on the basis of the technical solution of the present invention should not be excluded from the scope of the present invention. outside the scope of protection.

Claims (8)

1. A storage battery energy storage regulator, characterized in that it comprises: At least two charging and discharging management systems, the AC sides of which are connected in parallel to a common bus, and then connected to the high-voltage main bus through a transformer; the DC terminals of each of the charging and discharging management systems are connected to a battery pack, and the control system The storage battery pack performs two-way regulation of active power and reactive power at the PCC point formed with the high-voltage main busbar and the common busbar within the upper and lower limit voltage value ranges, so that the voltage and frequency of the PCC point are stable; A system main monitor, which exchanges information with each of the charging and discharging management systems through several CAN interfaces, and controls the external backup power supply to supply power to the high-voltage main bus or controls unloading load consumption according to the instructions of the charging and discharging management system The electric energy output by the high-voltage main busbar is removed to stabilize the voltage and frequency of the PCC point. 2. A storage battery energy storage regulating device according to claim 1, wherein each charge and discharge management system comprises: A voltage source inverter, which performs bidirectional adjustment of active power and reactive power between it and the PCC point, so as to stabilize the voltage and frequency of the PCC point; a plurality of electric energy element samplers, collecting the actual electric energy elements of the high-voltage main bus, the electric energy elements on the common bus between the voltage source inverter and the transformer, and the voltage at both ends of the battery pack; An analog-to-digital conversion module, which converts various electric energy elements collected by the electric energy element sampler into digital signals; A DSP core controller, wherein the PCC point voltage and frequency values, as well as the upper and lower limit voltage values at both ends of the battery pack are preset; The DSP core controller controls the voltage and frequency of the PCC point to a preset value according to the electric energy element input by the analog-to-digital conversion module, and simultaneously judges whether the voltage value at both ends of the battery pack exceeds the preset upper limit. , the lower limit voltage value, to control the work of the voltage source inverter and/or the main monitor of the system. 3. The battery energy storage regulating device according to claim 2, wherein the electric energy elements collected by the electric energy element sampler include voltage, frequency and current. 4. A battery energy storage regulating device as claimed in claim 2, characterized in that: when the DSP core controller judges that the actual voltage and frequency of the PCC point are greater than the preset voltage and frequency value, and the voltage across the battery pack is within the preset upper and lower limit voltage ranges, the voltage source inverter absorbs active power to stabilize the PCC point voltage and frequency to preset values. 5. A battery energy storage regulating device as claimed in claim 2, characterized in that: when the DSP core controller judges that the actual voltage and frequency values of the PCC point are greater than the preset voltage and frequency value, and the voltage value at both ends of the battery pack is equal to the preset upper limit voltage value, the DSP core controller controls the unloading load through the system main monitor to consume the electric energy output by the high-voltage main bus, so that The voltage and frequency of the PCC point are stable at preset values. 6. A battery energy storage regulating device as claimed in claim 2, characterized in that: when the DSP core controller judges that the actual voltage and frequency value of the PCC point is less than the preset voltage and frequency value, And when the voltage value at both ends of the battery pack is within the preset upper and lower limit voltage ranges, the voltage source inverter generates active power to stabilize the voltage and frequency of the PCC point to preset values. 7. A battery energy storage regulating device as claimed in claim 2, characterized in that: when the DSP core controller judges that the actual voltage and frequency value of the PCC point is less than the preset voltage and frequency value, And when the voltage value at both ends of the battery pack is equal to the preset lower limit voltage value, the DSP core controller starts an external backup power supply through the system main monitor to supply power to the high-voltage main bus, so that the PCC point Voltage and frequency are stable at preset values. 8. A battery energy storage regulating device as claimed in claim 1 or 2 or 4 or 5 or 6 or 7, characterized in that it also includes a host computer, which communicates with the system main monitor through the RS485 interface interaction, to remotely monitor and control the charge and discharge management system; the host computer includes a man-machine interface, which performs information interaction with the main monitor of the system through the CAN interface, to control the charge and discharge management system Conduct man-machine dialogue and remote control.

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